Opioid growth factor reverses the progression of clinical disease in established relapse‐remitting experimental autoimmune encephalomyelitis ő a model for multiple sclerosis (651.2)

Abstract

Relapse‐remitting multiple sclerosis (RR‐MS) is a chronic disorder involving inflammatory attacks on the CNS in 350,000 people in the U.S. RR‐MS reduces the quality of life, and eventually results in paralysis. OGF, chemically termed [Met5]‐enkephalin, was administered daily to female SJL/J mice with established relapse‐remitting experimental autoimmune encephalomyelitis (RR‐EAE). Mice were immunized with PLP139‐151 in complete Freund’s adjuvant, and beginning 2 days after initial behavioral signs received daily injections of OGF (10 mg/kg) or sterile saline. Within 9 days of treatment with OGF the mice had markedly reduced mean behavior scores relative to controls; the sum of the behavior scores was 140.1±14.4 for the RR‐EAE+Saline group in comparison to 72.2±11.5 for the RR‐EAE+OGF group. Disease severity scores were 16.3± 5 for RR‐EAE+Saline in comparison to 3.6±1.7 for OGF treated mice. No saline‐treated mouse had a complete remission, whereas 83% of OGF mice had complete remissions (behavioral score 蠄 0.5); the total length of time in complete remission was 9.1±3.4 days for the RR‐EAE+OGF animals over the course of the 40‐day experimental period. In summary, treatment with OGF initiated at the time of discernible disease reduced the intensity of the initial flair, reversed the progression of RR‐EAE, and resulted in complete clinical remission, supporting its use as a novel therapy for the treatment of MS.Grant Funding Source: Shockey Family Foundation